“One of these things is not like the other,” sang Zac Brown, almost under his breath. He was referring to himself, humbled as he was to find himself here Tuesday night (Sept. 13) in the company of certifiable legends at a benefit for Nashville’s Country Music Hall of Fame and Museum.

In actuality, none of these things was quite like the other on Tuesday’s bill — with the possible coupled exception of Vince Gill and Emmylou Harris, fellow Hall of Famers and friends of 35 years. Both have been part of the lineup for all three years these All for the Hall fundraising concerts have been in existence in Los Angeles, with Gill always playing the earthy host and Harris as his trusty, ethereal sidekick.
But the other slots at this high-priced charity “guitar pull” always end up introducing some wrinkles. There is usually a slot for the superstar-newcomer. Last year, that was Taylor Swift, and in 2011, it was Zac Brown filling the token role of the zeitgeist-y hitmaker who can’t believe he’s there even though he’s the biggest draw on the bill.

Gill usually also finds a slot for the rocker who is squarely on the periphery of country. One year, that was Chris Isaak. This time, it was Nashville resident and champion Sheryl Crow.

And there’s usually also one “what the hell is he doing here?” ringer from outside the genre. Last year, Lionel Richie. This year, Kevin Cronin of REO Speedwagon renown but no particular Nashville notoriety.

“I was thinking to myself, ‘These guys must think that I’m the singer from Diamond Rio,'” Cronin kidded.

Before the show got underway, CMT.com asked Brown backstage who he was most looking forward to sharing the stage with.

“Everybody,” affirmed the CMA Awards’ surprise entertainer of the year nominee. “Everybody on that stage has made their mark. I wasn’t sure that Emmylou Harris was a real person. I wanted to make sure that she wasn’t an angel. And I actually put my hand on her back a minute ago to take a picture, so she is a real human being. That was good to know.”

“Oh, it’s just because I’ve been around so long,” said Harris, sloughing off the hero worship.

As for the predictably peculiar lineups at these annual concerts at Club Nokia, she said, “I don’t think there’s a formula. I just kind of show up, and I know it’s going to be Vince and me, and I don’t worry about it. These in-the-round things always work because everybody started out sitting in a living room playing by themselves to a couple of people. So basically it’s just people doing what they started out doing.”

“I haven’t even decided what I’ll sing tonight,” said Gill, when asked if he’d be premiering material from his imminent Guitar Slinger album. (He ended up doing just one song from it, “If I Die,” a poignant co-write with Pistol Annies member Ashley Monroe.) “I never know at these things. Whatever someone sings before you will motivate you to sing something else.”

That proved to be exactly the case when, for a good half-hour, the performers all got to talking — and singing — about their favorite guitars. It all started when Brown gave a lengthy spoken introduction to his song, “Martin,” which, as you might know or expect, is not about MLK Jr. or even Martin Landau but his best wooden friend constructed by the C.F. Martin company.

“I’ve always been able to hide behind my guitar, even when I was young,” Brown told the crowd. “I started carrying it with me everywhere. I was ‘that guy.’ At camp, when I was 7 or 8, I finally got [someone to tell me] ‘Put the damn guitar down.’ It was my security blanket.”

His song, “Martin,” was about “a living thing — a guitar that is living, to me — from his birth to finding me.”

“I can relate to that,” said Cronin, going next. The REO singer related the story of how, as a kid, “I used to get my ass kicked for carrying a guitar.”

It’s hard to conceive of a time when that was the uncoolest thing imaginable, but when he placed a date on things changing, it all made sense.

“One day in ’64, the Beatles were on Ed Sullivan, and the next week, those same dudes who’d been kicking my butt for two years were asking if they could be in a band with me,” he said.

Cronin then performed “Music Man,” with accompaniment by Gill that led him to exclaim, “If I’d had that guitar solo on it, the song would have been a hit!”

Harris talked about her guitar, which she’d had since first coming out to California to sing with Gram Parsons in the early ’70s. (“Before Gram, I was just a bad waitress,” she explained.) The acoustic was damaged at an airport, and she believed the repair person “put it back together with popsicle sticks,” but she’s still playing it to this day and used it to sing her ode to Parsons, “The Road.”

Gill then sang his autobiographical ode to his favorite six-string companion, which he’s had since 1975: “This Old Guitar and Me.” He poignantly told of losing 50 guitars and 30 amps in last year’s Nashville flooding … and even “some of the cases were worth thousands” due to their age. One triumph he related was digging through the moldy debris and finally finding a Chet Atkins pick he had tucked inside one of the ruined cases. Perennial crush Gill also talked about how sweet Atkins’ widow, Leona, was on him. “When Leona turned 70, I popped out of her cake,” he noted. “Not very many people know that.”

“They do now. I’m tweeting it,” said Crow.

Other highlights included Gill’s opening version of “Bartender,” in honor of George Jones’ 80th birthday, a duet between Harris and Crow on a Carter Family song, Brown interpolating Van Morrison’s “Into the Mystic” into one of his own anthems, and a soaring rendition of Crow’s “If It Makes You Happy” that benefitted from Harris’ very happy-making harmony vocal.

For some of these artists, the collaborative nature of the evening translates to the recording studio. Before the show, Harris let slip that she is due to record a joint album with Rodney Crowell this fall.

“It was my idea,” she told CMT.com. “Actually, it’s been an unspoken — or spoken — thing over the years: ‘We’ve gotta do a record.’ I don’t know what it’s going to be, except that I’m not writing a darn thing for it! Right now, we’re in the formative stages, even though we’re definitely going to hit the first note around the middle of November.

“Besides writing songs, Rodney’s a great song finder, too. But I’m sure there are going to be some Rodney songs. There would have to be. But it all depends on what fits the philosophy of the album — which we don’t know yet!”